Livestock pen



FIG. 1 is a front perspective view of a livestock pen showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof; and,

FIG. 6 is a top elevational view thereof.

The dash-dash-dash broken lines represent portions of the livestock pen that form no part of the claimed design. The dash-dot-dash lines represent boundary lines and form no part of the claimed design. 

CLAIM The ornamental design for a livestock pen, as shown and described. 